Thank you for your time Grimm! It is also a lot slower just like mine.
Here is my summary: based on previous benchmarks the render time with the RTX 2060 and progressive refine should be around 2min 55sec without the RT cores of course. But since 2.79b there was already a 20% slowdown because of the reflective caustics (see: Slower Cycles GPU in Blender 2.8 Beta). So the estimated final rendering time in fact should be around 2min 20sec.
Just for comparison: I did a benchmark with Redshift 2.6.32 demo and the render time was (brute force) 2min 22sec. Note that under Redshift there is no reflective caustics with progressive rendering. I think at the same time Redshift will get a few of optimization soon and will be faster.
What I completely can’t understand:
Many people said it is, but Cycles doesn’t should be slow at all - see the render times above or like example there is E-Cycles. But to time to time Cycles will be just slower and slower approaching 2.80 stable. Shouldn’t it be the opposite? I don’t think the devs can’t have a single RTX card. I think the overall communication is misleading like example because of this: https://twitter.com/tonroosendaal/status/1064879909351378949